expect(
    reject([1, 2, 3, 4, 5], function(val) {
        return val % 2 === 0;
    })
).to.eql([1, 3, 5]);

expect(
    reject(
        [1, 2, 3],
        function(val) {
            return this.indexOf(val) > -1;
        },
        [1, 2]
    )
).to.eql([3]);
